A variety of devices are available for displaying the telephone number of a caller after a connection has been established between the parties for talking. One such device answers an incoming call by sending a message to the caller instructing that party to dial his own telephone number. That number is received by the device and compared with a directory of names and associated telephone numbers for logging that name and number for later display and review by the user. Such a device is disclosed in U.S. Pat. No. 4,304,968 which was issued Dec. 8, 1981 to Klausner et al. A disadvantage of these devices is that a caller must not only respond to the device's instruction, but will also be required to pay for the call, if it is a toll call.
Another device that is presently available is a telephone station set which gives customers the ability to view the telephone number of the calling party even while the phone is still ringing. The telephone station set takes advantage of a special service provided by the telephone company which sends the phone number of the caller during the silent interval between rings. Each number is decoded and displayed by equipment at the customer's premises. If a call is not answered the number is stored for later review. This special service may also include transmitting additional information such as personal messages and time of day, as well as other useful information. An example of this type of device is disclosed in U.S. Pat. No. 4,582,956, which was issued Apr. 15, 1986, to Carolyn A. Doughty. With such a device, however, the customer must depend on the telephone company for transmitting all desired information pertaining to that incoming call, including the name of the calling party.